Possible orographic and solar controls of Late Holocene centennial-scale moisture oscillations in the northeastern Tibetan Plateau

We present a record of lake-level changes from Hurleg Lake, a freshwater lake in the arid Qaidam Basin on the NE Tibetan Plateau, an area with few high-resolution paleoclimate records. The carbonate percentage and ostracode abundance show a consistent pattern with ∼200-year moisture oscillations during the last 1000 years. The moisture pattern in the Qaidam Basin is in opposite relation to tree-ring-based monsoon precipitations in the surrounding mountains, suggesting that topography may be important in controlling regional moisture patterns as mediated by rising and subsiding air masses in this topographically-complex region. Crosss-pectral analysis between our moisture proxies and solar activity proxy shows high coherence at the ∼200-year periodicity which is similar to Chinese monsoon intensity records, implying the possible solar forcing of moisture oscillations in the NE Tibetan Plateau.